Distribution transformer coil support



Dec. 6, 1949 BRQVERMAN 2,490,506

DISTRIBUTION TRANSFORMER COIL SUPPORT File d Nov. 14, 1946 Inventdr: Michael Braver-man,

His Attorney.

Patented Dec. 6, 1949 DISTRIBUTION TRANSFORMER COIL SUPPORT Michael Broverman, Pittaiield, Mala, alaignor to General Electric Company, a corporation of New York Application November 14, 1910, Serial No. 100,735

This invention relates specifically to support for electrical coils and more generally to improvements in induction apparatus.

In the assembly for transformers and reactors, a preformed conductive coil is usually mounted on a magnetic core. In some apparatus of this kind, such as distribution transformers, it is necessary to provide supports for the coil or coils so as to hold them in place against the action of displacing forces which arise under short circuit conditions.

In accordance with this invention, there is provided a novel coil support which is characterized by its simplicity and low cost. Its major element is a generally U-shaped bracket or strap, one edge of which cooperates with a spacer or wedge which is forced between it and the coil or coils to be supported. A novel and simple locking means is also provided for the wedge.

An object of the invention is to provide a new and improved induction apparatus.

Another object of the invention is to provide a novel, simple and inexpensive coil support for induction apparatus.

The invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

In the drawing. Fig. 1 is a partly broken away perspective view of a distribution transformer which embodies the invention; Fig. 2 is an enlarged detailed view of the coil support shown in Fig. l, and Fig. 3 is a view similar to Fig. 2 which shows the wedge in its retracted position and the locking tap in its original position before it is bent into place.

Referring now to the drawing, and more particularly to Fig. 1, there is shown therein the core and coil assembly of a typical distribution transformer. This consists primarily of a supporting frame I which embraces the outer edges of a three-legged magnetic core I. This core may consist of a pair of duplicate elliptical laminated magnetic loops 3 and 4 which are placed side by side so as to form a three-legged or shell type core. Mounted concentrically on the central leg of the core are a pair of conducting windings 5 and 0 which may, for example, be the high voltage I and low voltage windings respectively of the transformer. The coils are protectively insulated from the core by means of suitable sheet insulation I which may be made of pressboard, for example.

The coils I and 6 are supported firmly in posi- 3 Claims. (01. 248-416) of coil support assemblies 8 at the top and 9 at the bottom. Although only one each of these assemblies is shown in Fig. 1, it will be understood that actually there are four of each for the transformer, there being two of the assemblies 8 on each side of the transformer at the top and two of the assemblies 8 on each side of the transformer at the bottom.

Referring now to Fig. 2, the upper coil support assembly 8 comprises a generally U-shaped bracket or strap in for outwardly extending feet H which are attached to the frame i in any suitable manner such as by welding. Part III may readily be stamped out of commercial strip metal and because of its extreme simplicity and economy of material, it is relatively inexpensive. As will be seen in Fig. l, the bracket I0 is attached to the frame at an angle to the plane of the top of the coils in such a way that the part of the bracket nearest the center of the coils is also nearest the top surface of those coils and the bracket which is nearest the outer periphery of the coils is farthest away from the coils.

Located between bracket II and the sheet insulation I on top of the coils 5 and 6 is a wedge I! of any suitable material, such as wood. By driving the wedge from left to right, as viewed in Fig. 2, 'a downward clamping force can be exerted on the coil assembly.

For locking the wedge 12 in any position, it is provided with an upward extension l3 which fits into the space between the frame I and the sides of the U-shaped bracket II. The top surface of the projection I3 is inclined at an angle which is the reverse of the angle of the top surface of the wedge it. A locking tab or tongue H, which is formed in the central part of the bracket II by cutting slots IS in its top edge, is bent over into engagement with the reversely inclined top surface of the projection l3 and in this manner, wedge I2 is prevented from backing out and loosening its clamping action on the coil assembly.

Fig. 3 shows the position of the parts before the wedge I2 is driven home and before the locking tab it is bent into position.

The bottom coil supporting assemblies 9 are similar to the upper coil supporting assemblies 8 but it is unnecessary to have a wedging action take place at both top and bottom and, therefore, the U-shaped strap members ll may be mounted parallel with the end plane of the coils and spacers It may be employed which are parallel sided instead of being wedge-shaped as are the members l2. Preferably, the members It have downtion on the central leg ofthe core 2 by means wardly extending projections corresponding to 3 a the projections It on the wedges it which fit into responding to the locking tab it for fixing them in their transverse positions.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications can be made without departing from the invention and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is::.

1. A coil support for induction apparatuscomprising, in combination, a rectangular metal strap bent into the form of a generally U-shaped bracket with outwardly extending feet, spaced generally parallel cuts extending inwardly from one edge of said bracket at the middle thereof for defining a tongue piece therebetween, a wedge shaped member one side of which is adapted to bear against the other edge of said bracket, said wedge having a projection on said side extending into the spacebetween the three sides of said bracket, the end of said projection having a slope which is the reverse of the slope of said wedge. said tongue being adapted to be bent inwardly for engaging. said reverse slope so as to lock said wedge in position.

' prising, in combination. a metal strap bent into the form of a generally U-shaped bracket having outwardly extending feet, a spacer member for clamping a coil, said member having a surface which is normally pressed against an edge of the two legs of said generally U-shaped brackct, and a projection on said surface of said spacer member, said projection extending into the space between the three sides of said bracket for holding said spacer member in position.

3. A coil support for induction apparatus comprising, in combination, a metal strap bent into the form of a generally U-shaped bracket having generally outwardly extending feet, a wedge member, said wedge member having a surface which is normally pressed against an edge of the two legs of said generally U-shaped bracket, a projection on said surface of said wedge, said projection extendinginto the space'between the three sides of said bracket, said projection having a surface which is reversely sloped relative to said wedge, and means on said bracket for engaging said reversely sloped surface on said projection in order to lock said wedge in place.

MICHAEL BROVERMAN.

REFERENCES crrm UNITED STATES PA'I'ENTS Name Date Treanor Nov. 25, 1941 Number 

